Understanding Portrait Lenses Part 1: Exploring Photography with Mark Wallace


Hi everybody welcome to another episode of Exploring Photography right here on AdoramaTV I’m Mark Wallace and we are kicking off a two part series on which lens should I buy for photographing people. Now we know that we have lenses that are wide and lenses that are long and lenses that have big apertures and small but which one should you buy? Well specific to people photography there is sort of two different types of photography. We have street photos where we’re out and about, in cities and shooting things and most people agree that you should use a wide-angle lens for that and then you have in the studio professional portraits and headshots and most people also agree that you should use a long lens with a wide open aperture to shoot those types of things and so we’ve got long lenses for studios and wide lenses for Street. Why is that, and can you mix those and break the rules? Of course you can, but let’s talk about the things that we consider when we’re making people portraits. There are two things that are really important to us. One is depth of field, that’s how much of our image is in focus and the other is field of view. Now that’s how much our lens can see. I’ve already made a bunch of videos on depth of field and so make sure you check the links in the description of this video to see those but we understand that there are three things that effect depth of field; the length of our lens the distance from our subject and our aperture value. So what happens when we change those things up, with different types of lenses? Well to understand that, we need to start with field of view. That is how much our lens can see and so it’s measured in degrees and so for example a 21mm lens can see about 82 degrees. A 35mm lens sees 55 degrees. A 50mm lens can see about 40 degrees A 70mm lens has about a 29 degree field of view and a 200mm lens has about a 10 degree field of view. But don’t forget that field of view isn’t just horizontal its vertical and that means if you want to fill the frame on a 200mm lens well you don’t have to be very close to your subject if you want to fill the frame on a 21mm lens the same way we have to get really really close and that changes our perspective. Let me help you understand this and we have some mannequins back here that are really going to help us put this into view. So let’s say for example I’ve got my fingers here and I got them close to my face. Well my fingers look about right. Right? They look proportional but if I get closer to the lens and I get my fingers and I get them close to the lens well now I’m going to smash my head, crunch-crunch-crunch My fingers haven’t changed size but as I get closer and closer to the lens they get larger and larger and larger and that is what we call Perspective and some people confuse that and call it Distortion, so let’s really dig into this and show you on these mannequins here how this works, so I have two two little mannequins here. This girl here, I don’t know, we’ll call her Nancy and we have, I don’t know, Sylvia back there and we’re not using these because of budget cuts and we can’t afford models but we want these to be absolutely still and I’m using a 24-105mm lens, so I’ve got a wide angle lens and I’ve got a long lens and this is a zoom lens because all three of these things are going to come into effect when we’re thinking about lenses for portrait photography. So the first thing I want to do is I want to show you the difference between getting close with my feet, zooming in with my feet and zooming in with the lens that will change my perspective and it’ll change the size of things in relationship to each other so we’re going to make sure we see everything here and the first thing I’m going to do is I’m going to put my lens at its widest setting 24mm and I’m going to take a picture of our first mannequin face here I’m going to get about as close as I can get. I’m going to try to keep the size of the front mannequin the same in the frame. So I’m going to take a picture and we can see that this mannequins face looks really big, in contrast to the mannequin behind. Even though these have the exact same size of face there the same type of mannequin but this one looks huge. That one looks really really far away. Now I’m going to back up and I’m going to zoom in and I’m going to fill the frame at the same, I’ve got some guidelines here I’m going to make sure that its head is about the same and take another shot and now we can look at these two pictures back-to-back and we can see that our perspective, in other words how big this mannequins face is compared to that mannequins face changes radically when we step back and we zoom in and so the point of that is an exaggeration because it’s not just mannequin faces back and forth, it’s the nose and the ears and the lips and so if you get really close noses are closer to the camera lens than the ears and so it makes the faces of people look wonky. So when you’re getting close to fill the frame, some things happen. The perspective changes. We can see a lot of the background and the shape of people’s faces change because the nose is closer to the lens than the ears, and the background. So let me show you what happens if i zoom. So I’m going to come back here and I am going to have a wide shot. I’m going to take a picture of our
mannequins and with this wide-angle lens you can see everything, but notice the relationship, the size of the mannequin face in the first shot, then I’m going to zoom in I haven’t moved my position when I take another shot here and you’ll look at that. Now notice in both of these images that the size of the faces in relationship to each other are the same so that means that when we zoom our lens the subjects and everything in our field of view changes size in the same relative way to each other. Everything gets bigger and smaller in relationship to each other but when we walk and we oom with our feet things that are close to the lens get much larger than things in the background and that has a huge impact on the way we shoot. Now to understand this a few years ago I went into an old studio and I shot a series of images and now we can start comparing things specifically Depth of Field, Field of View and this Distortion. So let’s look at that right now. Let’s dive into our little experiment now I’ve taken a series of images of this coffee creamer and in each image I’ve tried to keep the coffee creamer about the same size in each image, so to do that I just put it on an old tripod. Now at the bottom of the screen you’ll see our ISO value that’s just there for your information. On the left hand side though is the aperture value, that’s really important and on the right hand side is the focal length. That’s also really important so let’s start with an 85mm lens. Notice our Depth of Field is pretty nice this is f16 at 85mm. I’m pretty close to the coffee creamer but you can still see behind the coffee creamer the wood on the right. Those boards over there, an orange ladder and a light stand another light stand and the legs of even another light stand. Now watch what happens when I change the aperture value and nothing else changes so we’re at the same distance. The only thing that’s going to change is our aperture value from f16 to f1.2 Notice that background just drops out and that is what our aperture can do with the longer lens. This is an 85mm lens, now notice the background and let’s go to a really long lens. This is a 200mm lens. Now notice we can only see the orange ladder the wood on the right has now disappeared. We can see an out-of-focus light stand next to that and nothing else. So the background is cleaned up quite a bit and notice I’m shooting at f2.8 and so things are nice and out-of-focus and I’ve tried to keep that coffee-mate about the same size which means I’ve had to back up considerably. Now let’s take a look at this next image to our 16mm lens a wide-angle lens. Now notice we’re still at f2.8, f2.8 here, f2.8 here. 200mm lens notice the background is really nice and clean. We only see the ladder and the light stand. When we go to our 16mm lens, notice we can now understand the environment even though we’re still at f2.8, our Depth of Field isn’t as shallow. We can identify things in this image. We can see that ladder back there we can see the wood to the right, we can see the walls, the coffee table, we can see some smudges over there by the door. So it’s not just the aperture value that gives us that shallow Depth of Field it’s also of the size of our lens, the focal length of our lens, with this one we’re really, really close. Now watch what happens when we just walk backwards, so again we’re still at f2.8 but I’m just going to take about 10 steps back, about 10 feet. Watch what happens BAM! Now everything is in focus. Everything looks good, nothing is distorted and we can clearly see everything but our aperture value, our ISO and our focal lengths have all remained the same. It’s just moving back and this is why wide-angle lenses are loved by street photographers because those lenses sort of pull us into the scene, we can open up our aperture and still have almost everything in focus and we can even get close to really exaggerate things. Well now that we know this, this explains why in a studio normally what you want to do is use a long lens and zoom in and out so everything stays in proportion to each other, but when we’re doing street photos then we want to see more of the environment, more of the background we want everything in focus, well we use a wide-angle lens we can get close and we can really exaggerate things to get dramatic effects. Now the question is are there exceptions to this rule? Absolutely. In fact I’ve got two friends that have really broken the rules. One of them his name is Scott Jarvie and he actually used a fisheye lens and a Ring Flash to create some really fun portraits and events he calls it the Jarvie window. I think these images are crazy fun and it totally breaks the rules with fisheye lens for portraits and then of course Kenna Klostermann, we talked to her in a previous episode about a year and a half ago I think and she talked about how she makes Street portraits instead of street photography she uses a longer lens. She isolates her subject, she gets rid of the background and she makes traditional portraits ike you would in the studio, but out on the street and so of course there are many people that are breaking the rules using wide-angle lenses in the studio, using long lenses out on the street, but it’s up to you. Now that you know how these different lenses behave and what they do to your subjects you can choose your own style. Well next week we’re going to hop into a small studio. We’re going to start talking about well can you really use a wide lens or a long lens in a small space and what’s appropriate
and what’s not appropriate? So that’s coming to you on AdoramaTV next week on Exploring Photography so make sure you subscribe so you don’t miss a single thing. Well thanks so much for joining me this week. Make sure you check out the links that are in the description of the video. Also check out the Adorama Learning Center for more information on all this stuff and it’s going to be awesome for you. Thanks for joining me I’ll see you again next time.

Leave a Reply

Your email address will not be published. Required fields are marked *